David Maxine's Oz blog along with mine (and if you haven't, why not?), you'll see he and his partner Eric Shanower have stuck with the Bradford Exchange's editions of reprints of the Oz books. If you've read his blogs, you know why I say "reprint." (If only the Bradford Exchange would say that.)
Anyway, in the comments and even the blogs themselves, you might have noticed mentions of Books of Wonder's editions of the Oz books. Since these editions are still very much available, it might seem odd to talk about them, especially as most Oz fans own a set.
This series began in 1985 with a reprint of The Marvelous Land of Oz utilizing all the color plates of the original edition as well as reproductions of the original pages, changes being made to the copyright page, title page, and spine to indicate the actual publisher. William Morrow did the actual publishing of the book, putting a book just about every bit as handsome as the original edition out in the wide open book market.
Other changes were made as well. The original endpapers showed an image of the Woggle-Bug, Tip, and Jack Pumpkinhead cheering as the Scarecrow and Tin Woodman rode in a wagon being pulled by the Sawhorse, except instead of Neill artwork for the two in the wagon, photographs of Fred Stone and David Montgomery (who played them in the original Oz musical) in full costume were used instead. This also required a slight redesign of the title page, as the original mentioned the endpapers. In addition, a new dustjacket was designed.
Overall, fans were not fussed about these changes. Having such a high quality edition was enough. In 1987, The Wonderful Wizard of Oz appeared, also in a faithful reproduction of the first edition (with alterations for it being as different publisher) without any artwork dropped. (Rather than a photo-facsimile, it seems some color elements were re-done, however, the method of doing these was faithful to the original's design.)
From that time on to the year 2000, all fourteen of Baum's novels were treated to such editions. Also, Little Wizard Stories of Oz was reprinted. The Road to Oz was printed on colored paper, just like the original edition, though I've heard some say the coloring of the paper and the placement isn't exactly the same. In The Emerald City of Oz, the original color plates had been embellished with metallic green ink. Since this proved too costly for Books of Wonder to replicate, green ink with gold glitter was utilized instead.
Controversially, The Patchwork Girl of Oz saw a couple text edits and an illustration dropped in light of politically correct sensibilities. As the Books of Wonder editions were not actually facsimiles (though it seems their marketing people screwed up a bit), these changes can be overlooked, especially as other editions without the edits remain. However, no mention of the alteration is in the book. Eric Gjovaag goes into this controversy in greater detail in this online column.
Rinkitink in Oz also saw an illustration dropped, but this time, it was noted on the copyright page.
Because the Books of Wonder/William Morrow (now Harper Collins) editions have been going for over 25 years, there have been some changes. Early versions used textured boards to simulate the original cloth binding. At some point (possibly when Harper Collins took over), this was dropped and slick case-bound covers (with all the images in the appropriate colors) were used instead. (This change caused their Ozma of Oz to become thicker. I've seen both versions.)
It's also worth noting that the dustjackets were not always replicas of the originals. Now, they use a stylized design on the spine, and the original dustjacket designs of the first three books were not used at all. (Their edition of The Road to Oz was the first to use a gold background on the dustjacket image since the original editions. Reilly & Britton had dropped and changed it after a time.) In addition, Peter Glassman provided an afterword to all the books, except Tik-Tok of Oz where a small note appeared in the front matter. Also, listings of other Books of Wonder titles may be seen.
In 2000, along with Glinda of Oz's release, The Wonderful Wizard of Oz was re-released by Book of Wonder and Harper Collins in a centennial edition, this time made taller to match the later Oz books as well as a new dustjacket design. This version also used a textured cover.
Overall, Books of Wonder did a wonderful job reprinting the Oz books. The text is still easy to read and the illustrations are printed clearly. To be sure, I recently scanned an image from one of their Marvelous Land color plates at a high dpi and zooming in, it quickly broke up into dots and pixels. Given the changes in printing technology (we still use three color printing, but our means of printing it have changed), this is understandable, and it looks just fine in print to the naked eye. (It might also be a way to prevent people from pirating their restoration work.)
If you're not interested in (or feel you could care for) a set of first or early edition Oz books, Books of Wonder is your best choice. Given the noted changes, though, there is yet a market for "exact replicas" of the original editions, but that void has yet to be filled.